Various medical conditions result in pathologic collections of bodily fluids. One such conditions is congestive heart failure (CHF), which causes the heart to be unable to effectively meet the oxygen needs of other organs. CHF usually occurs in adults after an injury to the heart, for example, after myocardial infarction, which causes the pumping action of the heart to be ineffective. CHF may also occur in the presence of a near-normal cardiac function under conditions of hi) 11 demand, for example, because of an increase of blood volume due to retention of salt and water or because of tachycardia. These compensatory changes burden the cardiac function, leading to progressive CHF.
In terms of incidence, prevalence, morbidity, and mortality, the epidemiologic magnitude of CHF is staggering. In the United States, the estimated annual cost of heart failure is $60 billion. Approximately one million U.S. hospital admissions per year are attributable to a primary diagnosis of acutely decompensated heart failure and the estimated annual cost of inpatient care for CHF patients is $23 billion.
Until recently, the only therapies for delaying progress of this illness were diuretics and heart-assist devices. Fluid accumulation related to CHF is typically treated by diuretics in the early stages of the condition, but over time the body builds resistance to diuretics and the patient then begins to retain fluid. Fluid and salt restrictions may be imposed, but despite these measures, most patients continue to accumulate fluid with cardiac function deteriorating over time, which results in further fluid accumulation until the patient receives a heart transplant or succumbs to his illness.
In three recent publications, the use of peritoneal dialysis was explored in the treatment of refractory CHF: COSTANZO ET AL., Early Ultrafiltration in Patients with Decompensated Heart Failure and Diuretic Resistance, J. Am. Coll. Cardiol. 2005; 46: 2047-2051, HOULBERG ET AL., Terminal right heart failure due to complex congenital cardiac disease successfully managed by home peritoneal drainage, Cardiol. Young 2003; 13: 568-570, and ORTIZ ET AL., Long-term automated peritoneal dialysis in patients with refractory congestive heart failure, Advances in Peritoneal Dialysis, 2003; 19; 77-80. In each of these publications, the patients were subjected to standard peritoneal dialysis and their conditions stabilized or even improved. This treatment requires the patients to undergo peritoneal dialysis exchanges, with the use of an external catheter and great risk of infection.
Various devices have been disclosed in the prior art for removing excess fluid from different body organs, for example, in U.S. Pat. No. 4,610,658 to Buchwald et al.; U.S. Pat. No. 4,850,955 to Newkirk; U.S. Pat. No. 6,132,415 to Finch et al.; U.S. Pat. No. 6,264,625 to Rubenstein et al.; and in U.S. Patent Application Publication 2005/0273034 to Burnett. The devices of the prior art, however, exhibit different shortcomings, for example, provide no system for preventing an excessive removal of fluids from a bodily cavity, or for preventing accumulation of tissue ingrowth into an implanted fluid collection system, which would cause the system to fail to operate properly over time.